Method anx



Aug. 12, 1947. p 2,425,293

METHOD AND APPARATUS'FOR MAKING FLEXIBLE INSULATION Filed July 8, 1944 INVENTOR ATTORNEY Patented Aug. 12, 1947 METHGD AND'APPARATUS FOR MAKING FLEXIBLE INSULATION PaulF. McDermott, Martinsville, N. J assignor to Johns-Manville Corporation, New York, N. Y., a corporationof New York;

Application July 8, 1944, Serial;No. 544,080"

7 Claims.

1 My invention relates to'the manufacture of flexible insulating materials and the like in the fgrr m of blankets, tapes, ropes and similar products and, more particularly, to the production of improyedarticles of. these types.

Afirincipalobject of the invention is th pro-.

vision. of a method,and apparatus for the economical commercial production of such products. Asdistinguished from previousproposals for the manufacture of insulating materials of this genoral type, such proposals involving the wrapping of a sheathing or covering around a preformed filler, the instant method includes the. fabricatingtofa flexible sheathing or sleeveloy knitting or the like, and the conveying of a loose, fibrous insulating. material such as asbestos into the.

sleeve substantially immediately after it is formed.

Another object of the invention is the provision. ofa method and apparatus for knitting. or otherwise fabricating a sleev around. a, forming member, and pneumatically conveying the. filling material through the. forming member into the sleeve while thelatter is maintained in distended condition by said forming member.

Briefly stated, the instant proces v and apparatus involves preferably a circular knitting-machine of substantially conventional construction adapted for, the production oftubular knit fabrics, Suitably the knitting machine'is of a character to, handle. finemetal strands whereby a protecting and confinin sleeve is providedwhich will permit the productto. be employed. under relatively. high temperature conditions and the likewhere the conventional materials fail. The apparatus includes a hollow tube extendin axially thli l h thev cylinder ofthe knitting machine or other forming mechanism, the hollow tube terminating in an open mouth. The tube serves as; a former or stretcher for the knitted sleeve and; in addition, serves as means for introducing a loose filling material into the sleeve while the latter is maintained in. its distended. condition nihetube.

My invention will be more fully understood and further objects and advantages thereof will become apparent when reference is made to the more detailed description of. the, preferred em-' bodiment thereof which is to follow, and to the accompanying drawings in which:

Fig. 1 is a perspective View of aninsulating blanket or the like formed in accordance with the instant method;

Fig.2 is'a diagrammatic, perspective view of an apparatus embodying the invention;

Fig. 3 is a sectional view on an enlarged scale.

taken onthe linestorms. 2;

2 Fig. 4- is a sectional view taken on'the line- 44 of Fig, 2; and

Fig. 5 is a view similar to Fig. 1 of a somewhat modified product of the apparatus and method.-

Referring now to the drawings, the product Ill disclosed inFig. 1 comprises an outer'flattened, tubular sleeve i2 and a preferably compressible filling I l. The product finds its principal field of'useas-an insulatingblanket or covering, and for this reason the description will refer to ma-- terials forthe sleeve and filling which adapt theblanket for such use. It will .beunderstood, however, that the product HLmay have other applications and that variousmaterials may be em-' ployed in its construction to provide therequired properties for different purposes.

Sleeve i2 is formed preferablyby'knitting:one-

or more strands in the form of a' holloW tube; Particularly where the material is to be subjected. to high temperatures, as for example, whereait' is to be employed as an insulation on turbines= or other equipment-where substantially elevate'd temperatures are encountered, the strands mak-: ing up the sleeve'are preferably of heat-resistant metals or alloys of metals such'as achrome'nickel steel, a nickel copper alloy and the like. Thefilling suitably comprises asbestos fiber ofknown I type such as Amosite fiber, although other asbestos fibers, mineral wool fibers, glass fibers and'- the like may be used.

sleeve has been reduced to provide a tape adaptedto be spirallywrapped or otherwise applied around the article to be insulated.-

Referringnow particularly'to Figs. 2-4 inclu-" sive, the apparatus for the manufacture ofz-pro'ducts such as those shown in Figs. 1 and 5 com prises means indicated at I6 for the fabrication of a flexible, tubular sleeve or sheathing l2. Preferably means 16, as illustrated,'is a circular knitting machine of known type including a knitting head #3 carrying needles 29." One or more spools of the strand material from'which the sleeve is formed are supported from the machine .as indicated at 22, the strand extending from the supply through guide 24 to the knitting point." The knitted fabric is withdrawn downwardly by suitable take-off means comprising, for example;

knurled rolls 26 driven in timed relationship to the operation of the machine. rolls, traction belts or the like may be employed.

The drive for the machine and other conventional operatingparts, such as the needle cam structure and the like, have not been shown, and the parts described above have. been-showndiae;

In lieu of knurled grammatically as such features are of conventional or usual type and, per se, form no part of the instant invention.

In accordance with the invention a hollow tubular member 28 is supported to extend axially through the cylinder of the machine. Member 28 includes a flattened, downwardl opening mouth section 30 below the knitting head. The opposite end of member 28 is connected through a conduit or tube 29 with the discharge side of a fan or blower 32. A supply hopper or the like, indicated diagrammatically at 34, is in communication with the intake of fan 32 through a filling material metering device 36 of any conventional or desired construction. It 'will be understood that alternatively the fillin material may be introduced into tube 28 at the discharge side of the fan.

Below, but adjacent the mouth section 30 of the forming tube, and of similar flattened shape, is a suction device 38, comprising a housing 40, having a preferably continuous inwardly opening air intake port 42. Housing 40 is connected through line 44 to a suction fan or the like to provide constant withdrawal of air through port 42.

In the operation of the apparatus described above, and in carrying out the method of the invention, strand material of selected type is supplied from spool 22 and is fabricated into a seamless, tubular fabric, around forming member 28 by means l6. As previously stated such means is preferably a knitting machine but may constitute braiding equipment or the like. The tubular fabric is flattened and preferably somewhat distended as it is drawn by take-off members 26 over the mouth section 30 of the forming member. A filling material such, for example, as asbestos fibers, is supplied in loose or nodule form to supply hopper 34 and is fed therefrom at a predetermined rate by metering device 36. As the fibrous material enters duct 29 it is picked up by the airstream created by fan 32, and is carried therealong in air suspension into the forming member and through the open mouth thereof into the newly formed flattened sleeve.

The quantity of the filling material may be controlled as desired, as indicated above, but is preferably sufficient to snugly fill the distended sleeve, the airstream serving, in addition to its carrying function, as an impacting medium to compress the material within the sleeve. The air carried with the filling material escapes through the open mesh of the sleeve and is drawn off by suction means 38. The suction means additionally serves to collect and remove the dust given ofi by the fibrous filling.

The flexible filled sleeve formed in a continuous length as described above, may be cut lengthwise into units of any suitable size for any selected purposes. If desired, the ends of the severed sections may be closed as, for example, by stitching or any other suitable means. As indicated by Figs. 1 and 5, the material may be made either in the form of a relatively large blanket or as a narrow tape or the like, merely by selection of the proper size knitting machine and forming member, and by controlling the flow of the filling material. Also the thickness and shape of the blanket or tape may be controlled by properly shaping the mouth section 33 of member 28. For example, products of approximately round or square cross-section can be made. It will also be understood that any of the products made as described above can be covered with additional knitted or braided jackets or otherwise further protected.

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to but that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.

What I claim is:

1. In a method of making a blanket or tape, the steps comprising knitting a tubular sleeve around a hollow forming member having an open end, drawing said sleeve from said forming member over said open end as it is knitted, pneumatically deliverin a loose fibrous material through said forming member and introducing it into said sleeve as said sleeve is drawn from said forming member, and withdrawing air through said sleeve adjacent the end of the forming member.

2. In a method of making a flexible insulation, the steps comprising knitting a tubular sleeve around a hollow forming member having a. flattened mouth section, drawing said sleeve from said forming member as it is knitted, pneumatically conveying a loose insulating material through said formin member and introducing it into said sleeve as said sleeve is drawn from said forming member, and withdrawing air through said sleeve adjacent the end of the forming member.

3. In a method of making a flexible insulation, the steps comprising forming a seamless, flexible sleeve around a hollow forming member having a flattened mouth section, drawing said sleeve from said forming member, pneumatically conveying a loose, fibrous insulating material through said forming member and forcing it into said sleeve as said sleeve is drawn from said forming member, the air employed for the pneumatic delivery of said fibrous material serving as an impacting medium against the material within the sleeve.

4. In an apparatus for the manufacture of flexible insulating materials and the like, a hollow forming member including an open mouth, means for fabricating a tubular sleeve around said forming member, means for drawing said sleeve over said open mouth, pneumatic means for delivering a loose filling material through said forming member and introducing it into said sleeve through said open mouth, and means for withdrawing air through said sleeve adjacent said.

open mouth.

5. In an apparatus for the manufactureof flexible insulation and the like, a hollow forming member including an open mouth, means for knitting a tubular sleeve around said forming member, means for drawing said sleeve as it is knitted over said open mouth, and means for pneumatically delivering a loose insulating material through said forming member and forcing it into said sleeve to fill the same at a point adjacent said open mouth.

6. In an apparatus for the manufacture of flexible insulating materials and the like, a hollow forming membe including a flattened mouth section, means for knitting a tubular sleeve around said forming member above said mouth section, means for drawing saidsleeve over said mouth section, means for pneumatically delivering a loose insulating material through said hollow forming member and forcing it into.'said sleeve, and means fo withdrawing air through said sleeve adjacent said mouth section.

7. In a method of making flexible insulation, the steps comprising fabricating a tubular sleeve around a hollow forming member having an open end, drawing said sleeve from said forming member as it is fabricated, pneumatically delivering a loose, compressible fibrous insulating material into said forming member and filling said sleeve therewith as it leaves said forming member, the air employed for the pneumatic delivery of said fibrous material serving as an impacting medium 10 against the material within the sleeve.

PAUL F. McDERMOTT.

REFERENCES CITED The following references are of record in the 15 file of this patent:

Number Number UNITED STATES PATENTS Name Date Lesavoy Aug. 4, 1942 Ford Aug. 9, 1938 Green Mar. 7, 1922 Simonson July 24, 1883 Bolze Sept. 1, 1885 Koppel Oct. 10, 1939 Fether Nov. 16, 1943 FOREIGN PATENTS Country Date Great Britain Apr. 12, 1923 

